5 Written questions
5 Matching questions
- what is a machine?
- what is a screw?
- What are compound machines?
- ^ ^ Doing work?
- if you throw a ball, are you doing work? Explain.
- a a device that helps make work easier by changing the size or direction of a force.
- b you are only doing work on the ball as long as you are directly putting a force on it, in other words, when you are touching it.
- c a inclined plane that is wrapped in a spiral, usually on a rod, but not always.
- d Yes
- e a machine made of two or more simple machines. example: scissors, can openers
5 Multiple choice questions
- a simple machine that is made of a circular object connected to a rod.
- is a measure of how much of a machines energy is wasted, overcoming friction. No machine is 100% efficient, becuase there are always surfaces rubbing together.
- pushing a piece of heavy furniture up a ramp requires less input force, from you, than just lifting it up.
- turn a door knob (the wheel) the axle moves, to unfasten the door.
- W= F x D, the unit Joule
5 True/False questions
What two things do we need to know to calculate work? → we need to know the size of the force that was put on the object, and how far the object moved.
^ ---> Doing work? → Yes
What is the fulcrum of a lever? → P=W / T, the unit Watts
^ <--- Doing work? → Yes
What is the scientific meaning of the word "work"? → P=W / T, the unit Watts